A long-term prevention study with oxprenolol in coronary heart disease.

We carried out a randomized double-blind controlled secondary-prevention trial of oxprenolol over seven years. Forty milligrams of oxprenolol or placebo was given twice daily to 1103 men 35 to 65 years old who had an acute myocardial infarction between 1 and 90 months previously. Overall, there was no difference in mortality or cardiac events between the placebo and oxprenolol groups. The major influence on prognosis was the time at which treatment was started after infarction. In 417 patients in whom treatment was started within four months of infarction oxprenolol increased the six-year cumulative survival rate from 77 to 95 per cent (P less than 0.001). In 274 patients with treatment starting between 5 and 12 months of infarction the survival rate was similar in the two groups, but in 412 patients entered between 1 and 7 1/2 years after their first infarction oxprenolol reduced the six-year survival rate from 92 to 79 per cent (P = 0.002). The increased mortality in this latter group mainly occurred late after withdrawal from active treatment. The value of low-dose oxprenolol in secondary prevention appears to be confined to patients treated relatively soon after myocardial infarction.